/*
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You under the Apache License, Version 2.0
 * (the "License"); you may not use this file except in compliance with
 * the License.  You may obtain a copy of the License at
 *
 *    http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package org.apache.dolphinscheduler.plugin.task.sqoop.generator;

import org.apache.dolphinscheduler.plugin.task.sqoop.SqoopJobType;
import org.apache.dolphinscheduler.plugin.task.sqoop.SqoopTaskExecutionContext;
import org.apache.dolphinscheduler.plugin.task.sqoop.generator.sources.HdfsSourceGenerator;
import org.apache.dolphinscheduler.plugin.task.sqoop.generator.sources.HiveSourceGenerator;
import org.apache.dolphinscheduler.plugin.task.sqoop.generator.sources.MySQLSourceGenerator;
import org.apache.dolphinscheduler.plugin.task.sqoop.generator.targets.HdfsTargetGenerator;
import org.apache.dolphinscheduler.plugin.task.sqoop.generator.targets.HiveTargetGenerator;
import org.apache.dolphinscheduler.plugin.task.sqoop.generator.targets.MySQLTargetGenerator;
import org.apache.dolphinscheduler.plugin.task.sqoop.parameter.SqoopParameters;

/**
 * Sqoop Job Scripts Generator
 */
public class SqoopJobGenerator {

  private static final String MYSQL = "MYSQL";
  private static final String HIVE = "HIVE";
  private static final String HDFS = "HDFS";

  /**
   * target script generator
   */
  private ITargetGenerator targetGenerator;
  /**
   * source script generator
   */
  private ISourceGenerator sourceGenerator;
  /**
   * common script generator
   */
  private final CommonGenerator commonGenerator;

  public SqoopJobGenerator() {
    commonGenerator = new CommonGenerator();
  }

  private void createSqoopJobGenerator(String sourceType, String targetType) {
    sourceGenerator = createSourceGenerator(sourceType);
    targetGenerator = createTargetGenerator(targetType);
  }

  /**
   * get the final sqoop scripts
   *
   * @param sqoopParameters           sqoop params
   * @param sqoopTaskExecutionContext
   * @return sqoop scripts
   */
  public String generateSqoopJob(SqoopParameters sqoopParameters, SqoopTaskExecutionContext sqoopTaskExecutionContext) {

    String sqoopScripts = "";

    if (SqoopJobType.TEMPLATE.getDescp().equals(sqoopParameters.getJobType())) {
      createSqoopJobGenerator(sqoopParameters.getSourceType(), sqoopParameters.getTargetType());
      if (sourceGenerator == null || targetGenerator == null) {
        throw new RuntimeException("sqoop task source type or target type is null");
      }

      sqoopScripts = String.format("%s%s%s", commonGenerator.generate(sqoopParameters),
          sourceGenerator.generate(sqoopParameters, sqoopTaskExecutionContext),
          targetGenerator.generate(sqoopParameters, sqoopTaskExecutionContext));
    } else if (SqoopJobType.CUSTOM.getDescp().equals(sqoopParameters.getJobType())) {
      sqoopScripts = sqoopParameters.getCustomShell().replaceAll("\\r\\n", "\n");
    }

    return sqoopScripts;
  }

  /**
   * get the source generator
   *
   * @param sourceType sqoop source type
   * @return sqoop source generator
   */
  private ISourceGenerator createSourceGenerator(String sourceType) {
    switch (sourceType) {
      case MYSQL:
        return new MySQLSourceGenerator();
      case HIVE:
        return new HiveSourceGenerator();
      case HDFS:
        return new HdfsSourceGenerator();
      default:
        return null;
    }
  }

  /**
   * get the target generator
   *
   * @param targetType sqoop target type
   * @return sqoop target generator
   */
  private ITargetGenerator createTargetGenerator(String targetType) {
    switch (targetType) {
      case MYSQL:
        return new MySQLTargetGenerator();
      case HIVE:
        return new HiveTargetGenerator();
      case HDFS:
        return new HdfsTargetGenerator();
      default:
        return null;
    }
  }
}
